U.S. patent application number 14/487217 was filed with the patent office on 2015-04-02 for electric steering apparatus for vessel propulsion apparatus, and vessel propulsion apparatus.
The applicant listed for this patent is YAMAHA HATSUDOKI KABUSHIKI KAISHA. Invention is credited to Makoto MIZUTANI, Morihiko NANJO.
Application Number | 20150093947 14/487217 |
Document ID | / |
Family ID | 52740602 |
Filed Date | 2015-04-02 |
United States Patent
Application |
20150093947 |
Kind Code |
A1 |
NANJO; Morihiko ; et
al. |
April 2, 2015 |
ELECTRIC STEERING APPARATUS FOR VESSEL PROPULSION APPARATUS, AND
VESSEL PROPULSION APPARATUS
Abstract
An electric steering apparatus for a vessel propulsion apparatus
includes a steering motor, a lock clutch, and a rotation stopper
mechanism. The steering motor generates a driving force to turn the
steering shaft joined to an outboard motor. The lock clutch
transmits a driving force from an input shaft to an output shaft
when a forward input to transmit a driving force from the steering
motor is generated, and shuts off the driving force transmission
from the output shaft to the input shaft when a reverse input to
transmit a driving force from the steering shaft is generated. The
rotation stopper mechanism is configured to switch between a lock
state in which the rotation stopper mechanism restricts rotation of
the casing and a release state in which the rotation stopper
mechanism releases the rotation restriction of the casing.
Inventors: |
NANJO; Morihiko; (Shizuoka,
JP) ; MIZUTANI; Makoto; (Shizuoka, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
YAMAHA HATSUDOKI KABUSHIKI KAISHA |
Iwata-shi |
|
JP |
|
|
Family ID: |
52740602 |
Appl. No.: |
14/487217 |
Filed: |
September 16, 2014 |
Current U.S.
Class: |
440/6 |
Current CPC
Class: |
B63H 23/30 20130101;
B63H 20/12 20130101; B63H 23/34 20130101; B63H 25/24 20130101 |
Class at
Publication: |
440/6 |
International
Class: |
B63H 20/12 20060101
B63H020/12; B63H 23/30 20060101 B63H023/30; B63H 23/34 20060101
B63H023/34; B63H 23/24 20060101 B63H023/24 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 1, 2013 |
JP |
2013-206512 |
Claims
1. An electric steering apparatus for a vessel propulsion
apparatus, the electric steering apparatus comprising: a steering
motor configured to generate a driving force to turn a steering
shaft joined to an outboard motor; a lock clutch including an input
shaft to which rotation is transmitted from the steering motor, an
output shaft configured to transmit the rotation transmitted to the
input shaft to the steering shaft, and a casing configured to
rotatably hold the input shaft and the output shaft, the lock
clutch being configured to transmit a driving force from the input
shaft to the output shaft when a forward input in which a driving
force is transmitted from the steering motor to the steering shaft
is generated, and to transmit a driving force from the output shaft
to the casing so as to shut off a driving force transmission from
the output shaft to the input shaft when a reverse input in which a
driving force is transmitted from the steering shaft to the
steering motor is generated; and a rotation stopper mechanism
configured to switch between a lock state in which the rotation
stopper mechanism restricts rotation of the casing and a release
state in which the rotation stopper mechanism releases a rotation
restriction of the casing.
2. The electric steering apparatus for a vessel propulsion
apparatus according to claim 1, further comprising a bearing
configured to rotatably support the casing.
3. The electric steering apparatus for a vessel propulsion
apparatus according to claim 1, further comprising: a steering
housing configured to house the steering motor and the lock clutch,
and define a rotation stopper adjusting hole extending from an
outside of the electric steering apparatus toward the lock clutch;
and a plug configured to move between a closed position at which
the plug closes the rotation stopper adjusting hole and an open
position at which the plug opens the rotation stopper adjusting
hole.
4. The electric steering apparatus for a vessel propulsion
apparatus according to claim 1, further comprising: a steering
housing configured to house the steering motor and the lock clutch,
and define a rotation stopper adjusting hole extending from an
outside of the electric steering apparatus toward the lock clutch;
wherein the rotation stopper mechanism includes an operation member
configured to close the rotation stopper adjusting hole and is
operated to switch the rotation stopper mechanism between the lock
state and the release state.
5. The electric steering apparatus for a vessel propulsion
apparatus according to claim 3, wherein the rotation stopper
adjusting hole is provided in a front wall of the steering housing,
and is disposed at a position viewable from a position on a
hull.
6. The electric steering apparatus for a vessel propulsion
apparatus according to claim 3, wherein the rotation stopper
adjusting hole is positioned such that the rotation stopper
adjusting hole and the casing of the lock clutch face each other in
radial directions of the casing.
7. The electric steering apparatus for a vessel propulsion
apparatus according to claim 1, wherein the rotation stopper
mechanism includes a friction mechanism configured to switch
between a lock state in which the rotation stopper mechanism
restricts rotation of the casing by a frictional force acting
between a pressed surface pressed against the casing and the
casing, and a release state in which the rotation stopper mechanism
releases the rotation restriction of the casing by weakening a
pressing force on the pressed surface against the casing to be
smaller than in the lock state.
8. The electric steering apparatus for a vessel propulsion
apparatus according to claim 7, wherein the friction mechanism
includes a tightening band including an inner surface on which the
pressed surface that has an annular shape surrounding the casing is
provided, and a pressing mechanism configured to adjust the
pressing force on the pressed surface against the casing by
changing an inner diameter of the tightening band.
9. The electric steering apparatus for a vessel propulsion
apparatus according to claim 8, wherein the tightening band
surrounds an entire circumference of the casing.
10. The electric steering apparatus for a vessel propulsion
apparatus according to claim 7, wherein the friction mechanism
includes a contact member including the pressed surface and a
pressing mechanism configured to adjust the pressing force on the
pressed surface against the casing by changing a force to push the
contact member toward the casing.
11. The electric steering apparatus for a vessel propulsion
apparatus according to claim 1, wherein the rotation stopper
mechanism includes a stopper mechanism configured to switch between
a lock state in which the stopper mechanism restricts rotation of
the casing by contact between the casing and a stopper member, and
a release state in which the stopper mechanism releases the
rotation restriction of the casing by releasing the contact between
the casing and the stopper member.
12. The electric steering apparatus for a vessel propulsion
apparatus according to claim 11, wherein the stopper mechanism
includes a plurality of rotation stopper portions provided on the
casing and aligned in a circumferential direction of the casing,
and a stopper member configured to move between a lock position at
which the stopper member faces any of the plurality of rotation
stopper portions and a release position at which the stopper member
and the plurality of rotation stopper portions do not face each
other, and restrict rotation of the casing by contact between any
of the plurality of rotation stopper portions and the stopper
member.
13. A vessel propulsion apparatus comprising: the electric steering
apparatus according to claim 1; a steering shaft configured to be
turned around a center line of the steering shaft by the electric
steering apparatus; and an outboard motor configured to turn around
the center line of the steering shaft together with the steering
shaft.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an electric steering
apparatus for a vessel propulsion apparatus, and a vessel
propulsion apparatus including the electric steering apparatus.
[0003] 2. Description of the Related Art
[0004] U.S. Pat. No. 8,246,400 discloses a plurality of electric
steering apparatuses for a vessel propulsion apparatus. Each
electric steering apparatus includes a motor that generates a
driving force to turn an outboard motor in the left-right
direction, and a lock portion that transmits only a driving force
transmitted from the upstream side to the downstream side.
[0005] The electric steering apparatus shown in FIG. 5 of U.S. Pat.
No. 8,246,400 (hereinafter, referred to as "first electric steering
apparatus") includes a lock release mechanism that shuts off a
driving force transmission path on the downstream side of the lock
portion to disable the lock portion. When a user manually steers
the outboard motor, the outboard motor is directly pushed by the
user in a state in which the driving force transmission path is
shut off.
[0006] The electric steering apparatus shown in FIG. 24 of U.S.
Pat. No. 8,246,400 (hereinafter, referred to as "second electric
steering apparatus") includes a rotating member that is disposed on
the upstream side of the lock portion, and rotates integrally with
a rotary shaft of the motor. When a user manually steers the
outboard motor, the rotating member is manually rotated by the user
in a state in which the driving force transmission path is not shut
off. Accordingly, the motor rotates, and the force of the user
applied to the rotating member is transmitted to the outboard motor
via the transmission path.
[0007] In the first electric steering apparatus, in the state in
which the driving force transmission path is shut off, the outboard
motor is manually steered by a user. Therefore, when the outboard
motor is manually steered, only members disposed on the downstream
side of the shut-off position move together with the outboard
motor. Therefore, the positional relationship between the upstream
side of the shut-off position and the downstream side of the
shut-off position changes. For example, the relationship between
the rotation angle of the motor and the steered angle of the
outboard motor changes. Therefore, after this, an operation to
restore the changed positional relationship is required.
[0008] In the second electric steering apparatus, the rotary shaft
of the motor rotates by the same rotation angle as that of the
rotating member. The rotation of the motor is decelerated, so that
when a user manually steers the outboard motor, the user is
required to rotate the rotating member a number of times.
Therefore, the steering operation is troublesome, and it takes time
to move the outboard motor to an intended steered angle.
SUMMARY OF THE INVENTION
[0009] In order to overcome the previously unrecognized and
unsolved challenges described above, a preferred embodiment of the
present invention provides an electric steering apparatus for a
vessel propulsion apparatus, the electric steering apparatus
including a steering motor, a lock clutch, and a rotation stopper
mechanism. The steering motor generates a driving force to turn the
steering shaft joined to an outboard motor. The lock clutch
includes an input shaft to which rotation is transmitted from the
steering motor, an output shaft that transmits the rotation
transmitted to the input shaft to the steering shaft, and a casing
that rotatably holds the input shaft and the output shaft. The lock
clutch transmits a driving force from the input shaft to the output
shaft when a forward input in which a driving force is transmitted
from the steering motor to the steering shaft is generated, and
transmits a driving force from the output shaft to the casing so as
to shut off the driving force transmission from the output shaft to
the input shaft when a reverse input in which a driving force is
transmitted from the steering shaft to the steering motor is
generated. The rotation stopper mechanism is configured to switch
between a lock state in which the rotation stopper mechanism
restricts (i.e., prevents) rotation of the casing and a release
state in which the rotation stopper mechanism releases the rotation
restriction of the casing.
[0010] With this arrangement, the lock clutch that shuts off a
reverse input is disposed in the transmission path extending from
the steering motor to the steering shaft. When a forward input in
which a driving force is transmitted from the steering motor to the
lock clutch is generated, the lock clutch transmits the driving
force from the input shaft to the output shaft. On the other hand,
when a reverse input in which a driving force is transmitted from
the steering shaft to the lock clutch is generated, the lock clutch
transmits the driving force from the output shaft to the casing and
shuts off the transmission of the driving force from the output
shaft to the input shaft.
[0011] When the rotation stopper mechanism is in the lock state,
rotation of the casing is restricted by the rotation stopper
mechanism. When a reverse input is generated, a force applied to
the output shaft of the lock clutch is transmitted to the casing.
In the lock state, rotation of the casing is restricted, so that
even if a reverse input is generated in the lock state, rotations
of the output shaft and the casing are restricted. Therefore, even
if a user pushes the outboard motor in the left-right direction or
a resistance of water caused by cruising is applied to the outboard
motor, the steered angle of the outboard motor does not change.
Therefore, even if the steering motor is not driven, the steered
angle of the outboard motor is kept constant.
[0012] On the other hand, when the rotation stopper mechanism is in
the release state, the rotation restriction of the casing by the
rotation stopper mechanism is released. In this state, when a user
pushes the outboard motor in the left-right direction, the force
applied to the outboard motor is transmitted to the output shaft
via the steering shaft. That is, a reverse input is generated. The
force applied to the output shaft is transmitted to the casing. In
the release state, the rotation restriction of the casing is
released so that the casing rotates together with the output shaft.
In other words, in the release state, the lock clutch is disabled
so that when a user pushes the outboard motor, in response to this,
the outboard motor turns in the left-right direction.
[0013] Thus, the rotation stopper mechanism enables the lock clutch
by restricting the rotation of the casing, and on the other hand,
the rotation stopper mechanism disables the lock clutch by
releasing the rotation restriction of the casing. Therefore, a user
can manually steer the outboard motor without shutting off the
driving force transmission path (without shutting off the physical
connection from the steering motor to the steering shaft).
Therefore, an adjusting operation after manual steering is reduced
or eliminated. Further, a user can turn the outboard motor in the
left-right direction by directly pushing the outboard motor so that
the user can easily move the outboard motor to a target steered
angle in a short time. In addition, the rotation stopper mechanism
is only required to make the lock clutch itself rotatable, so that
a simple structure is applied to the rotation stopper mechanism.
Accordingly, a complicated rotation stopper mechanism is not
required.
[0014] In a preferred embodiment of the present invention, the
electric steering apparatus preferably further includes a bearing
that rotatably supports the casing. The bearing is preferably a
rolling bearing or a sliding bearing.
[0015] With this arrangement, the casing is supported rotatably by
the bearing. Therefore, in the case where a torque is applied to
the casing when the rotation stopper mechanism is in the release
state, the casing smoothly rotates. If the casing does not smoothly
rotate when the outboard motor is manually steered, the resistance
to be applied to the outboard motor may increase and the outboard
motor may not smoothly move in the left-right direction. Therefore,
by supporting the casing rotatably by the bearing, the outboard
motor is manually smoothly steered with a smaller force.
[0016] In a preferred embodiment of the present invention, the
electric steering apparatus preferably further includes a steering
housing that houses the steering motor and the lock clutch, and
defines a rotation stopper adjusting hole extending from the
outside of the electric steering apparatus toward the lock clutch.
In this case, the electric steering apparatus preferably further
includes a plug that is movable between a closed position at which
the plug closes the rotation stopper adjusting hole and an open
position at which the plug opens the rotation stopper adjusting
hole.
[0017] With this arrangement, the steering motor and the lock
clutch are protected from water (including seawater and fresh
water) by the steering housing. Further, the rotation stopper
adjusting hole extending from the outside of the steering housing
toward the lock clutch is provided in the steering housing so that
a user can operate the rotation stopper mechanism from the outside
of the steering housing through the rotation stopper adjusting
hole. Specifically, a user can operate the rotation stopper
mechanism without inserting his/her hand into the steering housing.
In addition, the plug that opens and closes the rotation stopper
adjusting hole is provided so that a sealing property of the
steering housing is improved when operation of the rotation stopper
mechanism is unnecessary. Accordingly, the components (steering
motor, etc.) disposed inside the steering housing are more reliably
protected from water.
[0018] In a preferred embodiment of the present invention, the
electric steering apparatus preferably further includes a steering
housing that houses the steering motor and the lock clutch, and
defines a rotation stopper adjusting hole extending from the
outside of the electric steering apparatus toward the lock clutch.
In this case, the rotation stopper mechanism preferably includes an
operation member that closes the rotation stopper adjusting hole
and is operated to switch the rotation stopper mechanism between
the lock state and the release state.
[0019] With this arrangement, by an operation of the operation
member performed by a user, the rotation stopper mechanism is
switched between the lock state and the release state. A portion of
the operation member is disposed inside the rotation stopper
adjusting hole opened at the outer surface of the steering housing.
Therefore, a user can operate the operation member without removing
the operation member from the rotation stopper adjusting hole.
Further, the user is not required to insert a portion of the tool
into the steering housing through the rotation stopper adjusting
hole so that the user can more easily operate the rotation stopper
mechanism.
[0020] In a preferred embodiment of the present invention, the
rotation stopper adjusting hole is preferably disposed at a
position viewable from a position on the hull. In this case, the
rotation stopper adjusting hole may be provided in, for example,
the front wall of the steering housing.
[0021] With this arrangement, the rotation stopper adjusting hole
provided in the steering housing is disposed at a position viewable
from a position on the hull. Therefore, the user can operate the
rotation stopper mechanism from a position on the hull.
[0022] In a preferred embodiment of the present invention, the
rotation stopper adjusting hole may be positioned so that the
rotation stopper adjusting hole and the casing of the lock clutch
face each other in the radial directions of the casing.
[0023] With this arrangement, the rotation stopper adjusting hole
provided in the steering housing faces the casing in the radial
direction of the casing. In other words, at least a portion of the
rotation stopper adjusting hole is disposed at the same position as
that of the casing in the axial direction of the casing. Therefore,
the distance between the rotation stopper adjusting hole and the
casing becomes smaller than in the case where the rotation stopper
adjusting hole and the casing deviate from each other in the axial
direction. If the distance between the rotation stopper adjusting
hole and the casing is long, other members may be interposed
between the rotation stopper adjusting hole and the casing and
complicate the path from the rotation stopper adjusting hole to the
rotation stopper mechanism. Therefore, by reducing the distance
between the rotation stopper adjusting hole and the casing, the
path from the rotation stopper adjusting hole to the rotation
stopper mechanism is prevented from becoming complicated.
[0024] In a preferred embodiment of the present invention, the
rotation stopper mechanism preferably includes a friction mechanism
configured to switch between a lock state in which the rotation
stopper mechanism restricts rotation of the casing by a frictional
force acting between a pressed surface pressed against the casing
and the casing and a release state in which the rotation stopper
mechanism releases the rotation restriction of the casing by
weakening the pressing force on the pressed surface against the
casing to be smaller than in the lock state.
[0025] With this arrangement, the pressed surface provided on the
rotation stopper mechanism (friction mechanism) is pressed against
the outer peripheral surface of the casing. In the lock state, due
to a frictional force acting between the pressed surface and the
casing, rotation of the casing is restricted. In the release state,
the pressing force on the pressed surface against the casing is
weakened to be smaller than in the lock state, and accordingly, the
frictional force acting between the pressed surface and the casing
is reduced to be smaller than in the lock state. Accordingly, the
rotation restriction of the casing is released.
[0026] Thus, the state of the rotation stopper mechanism is
switched by changing the pressing force on the pressed surface
against the casing. Therefore, the rotation stopper mechanism
enables and disables the lock clutch without shutting off the
driving force transmission path. The position at which the pressed
surface is pressed may be an arbitrary position as long as the
position causes restriction of rotation of the casing, so that when
the lock clutch is enabled again after the outboard motor is
manually steered, the casing may not be returned to the original
position (position before the outboard motor is manually steered).
Therefore, the adjusting operation to enable the lock clutch again
is eliminated.
[0027] In a preferred embodiment of the present invention, the
friction mechanism preferably includes a tightening band including
an inner surface on which the pressed surface that preferably has
an annular shape surrounding the casing is provided, and a pressing
mechanism that adjusts the pressing force on the pressed surface
against the casing by changing the inner diameter of the tightening
band.
[0028] With this arrangement, the pressed surface to be pressed
against the outer peripheral surface of the casing is provided on
the inner surface of the tightening band of the rotation stopper
mechanism (friction mechanism). The inner diameter of the
tightening band is changed by the pressing mechanism. Accordingly,
the pressing force on the pressed surface against the casing is
increased or decreased, and the state of the rotation stopper
mechanism is switched. The pressed surface preferably has an
annular shape surrounding the casing. Therefore, the contact area
between the pressed surface and the casing increases. Therefore,
the casing is reliably held by the tightening band. Accordingly,
the rotation stopper mechanism reliably restricts rotation of the
casing in the lock state.
[0029] In a preferred embodiment of the present invention, the
tightening band may surround the whole circumference of the casing
at least in the lock state.
[0030] With this arrangement, the tightening band surrounds the
entire circumference of the casing so that the contact area between
the pressed surface and the casing is further increased.
Accordingly, the rotation stopper mechanism more reliably restricts
rotation of the casing in the lock state.
[0031] In a preferred embodiment of the present invention, the
friction mechanism preferably includes a contact member provided
with the pressed surface and a pressing mechanism that adjusts the
pressing force on the pressed surface against the casing by
changing a force to push the contact member toward the casing.
[0032] With this arrangement, the pressed surface to be pressed
against the outer peripheral surface of the casing is provided on
the contact member of the rotation stopper mechanism (friction
mechanism). The force to push the contact member toward the casing
is changed by the pressing mechanism. Accordingly, the pressing
force on the pressed surface against the casing is increased or
decreased, and the state of the rotation stopper mechanism is
switched. Therefore, the rotation stopper mechanism enables and
disables the lock clutch without shutting off the driving force
transmission path.
[0033] In a preferred embodiment of the present invention, the
rotation stopper mechanism preferably includes a stopper mechanism
configured to switch between a lock state in which the rotation
stopper mechanism restricts rotation of the casing by contact
between the casing and a stopper member, and a release state in
which the rotation stopper mechanism releases the rotation
restriction of the casing by releasing the contact between the
casing and the stopper member.
[0034] With this arrangement, the stopper member that comes into
contact with the casing is provided on the rotation stopper
mechanism (stopper mechanism). In the lock state, the stopper
member is disposed at a lock position (a position at which the
stopper member comes into contact or becomes contactable with the
casing). Therefore, even if a torque is applied to the casing in
the lock state, rotation of the casing is restricted by the contact
between the casing and the stopper member. In the release state,
the stopper member is disposed at a release position (a position at
which the stopper member cannot come into contact with the casing).
Accordingly, the rotation restriction of the casing is released.
Thus, the state of the rotation stopper mechanism is switched by
changing the position of the stopper member. Therefore, the
rotation stopper mechanism enables and disables the lock clutch
without shutting off the driving force transmission path.
[0035] In a preferred embodiment of the present invention, the
stopper mechanism preferably includes a plurality of rotation
stopper portions provided on the casing and aligned in the
circumferential direction of the casing, and a stopper member
movable between a lock position at which the stopper member faces
any of the plurality of rotation stopper portion and a release
position at which facing between the stopper member and the
plurality of rotation stopper portions is released. In this case,
the stopper mechanism restricts rotation of the casing by contact
between any of the plurality of rotation stopper portions and the
stopper member.
[0036] With this arrangement, a plurality of rotation stopper
portions that restrict rotation of the casing in conjunction with
the stopper member are provided on the casing. When the stopper
member is disposed at the lock position any of the plurality of
rotation stopper portions opposes the stopper member. Specifically,
the stopper member is disposed at a position at which the stopper
member comes into contact or is contactable with any of the
plurality of rotation stopper portions. Therefore, rotation of the
casing is restricted by contact between the rotation stopper
portions and the stopper member facing each other. When the stopper
member is disposed at the release position, facing between the
stopper member and the plurality of rotation stopper portions is
released. Accordingly, the rotation restriction of the casing is
released.
[0037] The plurality of rotation stopper portions are aligned in
the circumferential direction of the casing. The stopper member
restricts rotation of the casing regardless of which of the
rotation stopper portions the stopper member faces. Therefore, when
the lock clutch is enabled again after the outboard motor is
manually steered, the casing may not be returned to the original
position. Therefore, the adjusting operation to enable the lock
clutch again is eliminated.
[0038] Another preferred embodiment of the present invention
provides a vessel propulsion apparatus including the electric
steering apparatus, a steering shaft to be turned around the center
line of the steering shaft by the electric steering apparatus, and
an outboard motor that turns around the center line of the steering
shaft together with the steering shaft. With this arrangement, the
same advantageous effects as those described above are
obtained.
[0039] The above and other elements, features, steps,
characteristics and advantages of the present invention will become
more apparent from the following detailed description of the
preferred embodiments with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] FIG. 1 is a schematic side view showing a vessel propulsion
apparatus according to a first preferred embodiment of the present
invention.
[0041] FIG. 2 is a schematic side view showing an electric steering
apparatus before a swivel bracket is attached to clamp
brackets.
[0042] FIG. 3 is a schematic plan view showing the electric
steering apparatus in a state in which an upper cover is
removed.
[0043] FIG. 4 is a schematic plan view showing a rotation stopper
mechanism according to the first preferred embodiment of the
present invention.
[0044] FIG. 5 is a schematic sectional view showing a lock state of
the rotation stopper mechanism.
[0045] FIG. 6 is a schematic sectional view showing a release state
of the rotation stopper mechanism.
[0046] FIG. 7 is a schematic plan view showing a rotation stopper
mechanism according to a second preferred embodiment of the present
invention.
[0047] FIG. 8 is a schematic sectional view showing a lock state of
the rotation stopper mechanism according to the second preferred
embodiment of the present invention.
[0048] FIG. 9 is a schematic plan view showing a rotation stopper
mechanism according to a third preferred embodiment of the present
invention.
[0049] FIG. 10 is a schematic sectional view showing a lock state
of the rotation stopper mechanism according to the third preferred
embodiment of the present invention.
[0050] FIG. 11 is a schematic plan view showing a rotation stopper
mechanism according to a fourth preferred embodiment of the present
invention.
[0051] FIG. 12 is a schematic sectional view showing a lock state
of the rotation stopper mechanism according to the fourth preferred
embodiment of the present invention.
[0052] FIG. 13 is a schematic view showing rotation stopper
portions according to the fourth preferred embodiment of the
present invention.
[0053] FIG. 14 is a schematic sectional view showing a lock state
of a rotation stopper mechanism according to a fifth preferred
embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0054] In the following description, a vessel propulsion apparatus
1 in a reference posture is described. In the reference posture,
the crankshaft axis Ac extends in the vertical direction, and the
propeller shaft axis Ap orthogonal or substantially orthogonal to
the crankshaft axis Ac extends in the front-rear direction.
First Preferred Embodiment
[0055] As shown in FIG. 1, the vessel propulsion apparatus 1
includes a suspension device 2 attachable to the rear portion
(stern) of the hull H1, an outboard motor 3 joined to the
suspension device 2, and an electric steering apparatus 4 that
steers the outboard motor 3 in the left-right direction.
[0056] As shown in FIG. 1, the suspension device 2 includes a pair
of left and right clamp brackets 5 to be attached to the hull H1,
and a tilting shaft 6 supported in a posture extending in the
left-right direction by the pair of clamp brackets 5. The
suspension device 2 further includes a swivel bracket 7 attached to
the tilting shaft 6, and a steering shaft 8 supported in a posture
extending in the up-down direction by the swivel bracket 7.
[0057] As shown in FIG. 1, the outboard motor 3 is joined to the
upper end portion of the steering shaft 8 via a mount bracket 9 and
an upper mount MU. Further, the outboard motor 3 is joined to the
lower end portion of the steering shaft 8 via a lower mount ML. The
steering shaft 8 is supported by the swivel bracket 7 rotatably
around the steering shaft axis As (center line of the steering
shaft 8) extending in the up-down direction. The swivel bracket 7
is supported by the clamp brackets 5 via the tilting shaft 6. The
swivel bracket 7 is turnable around the tilting shaft axis At
(center line of the tilting shaft 6) extending in the left-right
direction with respect to the clamp brackets 5. As shown in FIG. 2,
the swivel bracket 7 includes tilting shaft holding portions 7a
that hold the tilting shaft 6, and a steering shaft holding portion
7b that holds the steering shaft 8 rotatably around the steering
shaft axis As.
[0058] As shown in FIG. 1, the outboard motor 3 includes an engine
10 that generates a driving force to rotate the propeller 14, and a
driving force transmitting device that transmits a driving force of
the engine 10 to the propeller 14. The driving force transmitting
device includes a drive shaft 11 joined to the engine 10, a
forward/reverse switching mechanism 12 joined to the drive shaft
11, and a propeller shaft 13 joined to the forward/reverse
switching mechanism 12. The outboard motor 3 further includes an
engine cover (cowling) 15 that accommodates the engine 10 and a
case 16 that houses the driving force transmitting device.
[0059] As shown in FIG. 1, the engine 10 is disposed over the drive
shaft 11. The drive shaft 11 extends in the up-down direction
inside the case 16. The center line of the drive shaft 11 may be
disposed on the rotation axis (crankshaft axis Ac) of the engine 10
or may deviate from the rotation axis of the engine 10. The upper
end portion of the drive shaft 11 is joined to the engine 10, and
the lower end portion of the drive shaft 11 is joined to the
propeller shaft 13 via the forward/reverse switching mechanism 12.
The propeller shaft 13 extends in the front-rear direction inside
the case 16. The rear end portion of the propeller shaft 13
projects rearward from the case 16. The propeller 14 is removably
attached to the rear end portion of the propeller shaft 13. The
propeller 14 is rotatable around the propeller shaft axis Ap (the
center line of the propeller shaft 13) together with the propeller
shaft 13.
[0060] The engine 10 is, for example, an internal combustion
engine. The engine 10 rotates in a fixed rotating direction. The
rotation of the engine 10 is transmitted to the propeller 14 by the
driving force transmitting device. Accordingly, the propeller 14
rotates together with the propeller shaft 13 to generate thrust to
cause the vessel travel forward or backward. The direction of
rotation to be transmitted from the drive shaft 11 to the propeller
shaft 13 is switched by the forward/reverse switching mechanism 12.
Therefore, the rotating directions of the propeller 14 and the
propeller shaft 13 are switched between the forward direction
(clockwise when the propeller 14 is viewed from the rear side) and
the reverse direction (direction opposite to the forward
direction). Accordingly, the direction of the thrust is
switched.
[0061] As shown in FIG. 3, the electric steering apparatus 4
includes a steering motor 17 that generates a driving force to turn
the steering shaft 8, steering force transmitting devices 28 to 31
that transmit a driving force on the transmission path of the
driving force (steering force) from the steering motor 17 to the
steering shaft 8, and a steering housing 19 that houses the
steering motor 17 and the steering force transmitting devices.
[0062] The steering motor 17 is an electric motor to be driven by
electricity. As shown in FIG. 3, the steering motor 17 is disposed
in a posture in which the rotation axis Am of the steering motor 17
extends in the left-right direction inside the steering housing 19.
The rotation axis Am of the steering motor 17 is disposed farther
rearward than the tilting shaft axis At. The steering motor 17
includes a cylindrical motor housing 25 that houses a rotor and a
stator which are not illustrated, an attaching flange 26 attached
to an end portion in the axial direction of the motor housing 25,
and a rotary shaft 27 projecting in the axial direction from the
attaching flange 26. The motor housing 25 and the attaching flange
26 are fixed to the steering housing 19. The rotary shaft 27 is
rotatable with respect to the steering housing 19.
[0063] As shown in FIG. 3, the steering housing 19 includes a
housing main body 20 that houses the steering motor 17 and the
steering force transmitting devices, and two side covers 21
disposed on the right and left sides of the housing main body 20.
As shown in FIG. 2, the steering housing 19 further includes an
upper cover 22 disposed over the housing main body 20. The side
covers 21 and the upper cover 22 are removably attached to the
housing main body 20. An opening provided at the upper end portion
of the housing main body 20 is closed by the upper cover 22, and
openings provided at the right side portion and the left side
portion of the housing main body 20 are closed by the two side
covers 21.
[0064] As shown in FIG. 3, the housing main body 20 includes a
peripheral wall having a U-shape opened rearward in a plan view,
and a bottom wall provided on the lower end portion of the
peripheral wall. The peripheral wall of the housing main body 20
includes a front wall 23 extending in the left-right direction, and
two side walls 24 extending rearward from the right end portion and
the left end portion of the front wall 23. As shown in FIG. 2, the
tilting shaft holding portions 7a of the swivel bracket 7 are
provided on the side walls 24 of the housing main body 20. The
steering shaft holding portion 7b of the swivel bracket 7 extends
downward from the housing main body 20. The housing main body 20 is
integral with the tilting shaft holding portions 7a and the
steering shaft holding portion 7b. Therefore, the housing main body
30 is integral with the swivel bracket 7. The housing main body 20
may be separate from the swivel bracket 7.
[0065] As shown in FIG. 3, the steering force transmitting devices
include a lock clutch 28 that transmits rotation of the steering
motor 17 toward the steering shaft 8, and a gear mechanism 29 that
decelerates the rotation transmitted from the lock clutch 28. The
steering force transmitting devices further include a ball screw
mechanism 30 that converts rotation decelerated by the gear
mechanism 29 into linear motion, and a motion converting mechanism
31 that convers linear motion converted by the ball screw mechanism
30 into turning of the steering shaft 8. The electric steering
apparatus 4 includes one or more (two in the example of FIG. 3)
bearings 32 that rotatably support the lock clutch 28, and a clutch
housing 33 that houses the bearings 32 and the lock clutch 28.
[0066] As shown in FIG. 3, the lock clutch 28 includes an input
shaft 34 into which the rotation from the steering motor 17 is
input, an output shaft 35 that outputs rotation input into the
input shaft 34 toward the steering shaft 8, and a casing 36 that
rotatably holds the input shaft 34 and the output shaft 35. The
input shaft 34 is joined to the rotary shaft 27 of the steering
motor 17, and the output shaft 35 is joined to the rotary shaft 27
of the steering motor 17 via the input shaft 34. The input shaft 34
and the rotary shaft 27 of the steering motor 17 are rotatable
integrally around the rotation axis Am of the steering motor 17.
The output shaft 35 and an upstream gear 37 of the gear mechanism
29 are rotatable integrally around the rotation axis Am of the
steering motor 17.
[0067] The lock clutch 28 is a reverse input shutoff clutch that
transmits torques in the forward direction and the reverse
direction from the input shaft 34 to the output shaft 35, and shuts
off (i.e., prevents) transmission of torques from the output shaft
35 to the input shaft 34 (for example, "torque diode (registered
trademark)" made by NTN Corporation). The lock clutch 28 transmits
a torque from the input shaft 34 to the output shaft 35 when a
forward input to transmit a torque from the steering motor 17 to
the steering shaft 8 is generated. The lock clutch 28 further
transmits the torque from the output shaft 35 to the casing 36 and
shuts off transmission of the torque from the output shaft 35 to
the input shaft 34 when a reverse input to transmit the torque from
the steering shaft 8 to the steering motor 17 is generated.
[0068] As shown in FIG. 3, the casing 36 of the lock clutch 28 is
disposed inside the clutch housing 33. The bearings 32 surround the
casing 36 in the circumferential direction Dc (refer to FIG. 5) of
the casing 36 inside the clutch housing 33. The two bearings 32 are
spaced apart by an interval in the axial direction Da of the casing
36. The bearings 32 are supported by the clutch housing 33, and the
casing 36 is supported by the clutch housing 33 via the bearings
32. The casing 36 is supported rotatably by the bearings 32, and is
rotatable with respect to the steering housing 19. On the other
hand, the casing 36 is fixed in the axial direction thereof, and is
immovable in the axial direction with respect to the steering
housing 19. As described below, the casing 36 is fixed in the
circumferential direction Dc of the casing 36 by the rotation
stopper mechanism 54.
[0069] As shown in FIG. 3, the clutch housing 33 is disposed inside
the steering housing 19. The clutch housing 33 is disposed on the
lateral side of the center CW in the width direction of the
outboard motor 3 (vertical plane that divides the outboard motor 3
in the reference posture into two halves in the left-right
direction). The clutch housing 33 is disposed farther forward than
a ball screw 40. The clutch housing 33 and the steering motor 17
are aligned in the axial direction of the steering motor 17. The
rotary shaft 27 of the steering motor 17 is disposed inside the
clutch housing 33. The clutch housing 33 is fixed to the attaching
flange 26 of the steering motor 17 by bolts, for example. The
clutch housing 33 is fixed to the steering housing 19 via the
steering motor 17, and is immovable with respect to the steering
housing 19.
[0070] As shown in FIG. 2 and FIG. 3, the gear mechanism 29
includes a plurality of reduction gears that transmit rotation from
the lock clutch 28 to the ball screw mechanism 30. The plurality of
reduction gears include an upstream gear 37 disposed on the
rotation axis Am of the steering motor 17, a downstream gear 39
disposed on the rotation axis of the ball screw 40 described below,
and one or more intermediate gears 38 disposed between the upstream
gear 37 and the downstream gear 39. The upstream gear 37 rotates
integrally with the rotary shaft 27 of the steering motor 17, and
the downstream gear 39 rotates integrally with the ball screw 40.
The rotation of the upstream gear 37 is transmitted to the
downstream gear 30 via the intermediate gear 38. Accordingly, the
rotation of the steering motor 17 is transmitted to the ball screw
mechanism 30.
[0071] As shown in FIG. 3, the ball screw mechanism 30 includes a
ball screw 40 that is driven to rotate by the steering motor 17,
and a cylindrical ball nut 41 that surrounds the ball screw 40 via
a plurality of balls. The ball screw 40 and the ball nut 41 are
disposed farther rearward than the steering motor 17 inside the
steering housing 19. The ball screw 40 extends in the left-right
direction on the rear side of the steering motor 17. Both end
portions of the ball screw 40 are supported by the steering housing
19. The ball screw 40 is rotatable around the center line of the
ball screw 40 with respect to the steering housing 19. The rotation
axis of the ball screw 40 and the rotation axis Am of the steering
motor 17 are parallel or substantially parallel to each other. When
the ball screw 40 rotates around the center line of the ball screw
40, the ball nut 41 moves in the axial direction of the ball screw
40 along the ball screw 40. Accordingly, the rotation of the ball
screw 40 is converted into linear motion of the ball nut 41.
[0072] As shown in FIG. 3, the motion converting mechanism 31
includes a steering pin 42 that moves in the axial direction of the
ball screw 40 together with the ball nut 41, and a steering arm 43
that turns around the steering shaft axis As together with the
steering shaft 8. The steering pin 42 extends downward from the
ball nut 41. The steering arm 43 extends from the steering shaft 8
to the steering pin 42. The root portion of the steering arm 43 is
joined to the steering shaft 8, and the tip end portion of the
steering arm 43 is disposed below the ball nut 41. The steering arm
43 includes a fork portion 44 provided on the tip end portion of
the steering arm 43. The steering pin 42 is disposed inside the
fork portion 44. When the steering pin 42 moves in the axial
direction of the ball screw 40 together with the ball nut 41, the
inner surface of the fork portion 44 is pushed by the steering pin
42, and the steering arm 43 turns. Accordingly, the outboard motor
3 and the steering shaft 8 turn around the steering shaft axis
As.
[0073] As shown in FIG. 3, the electric steering apparatus 4
includes a steered angle detection device 45 that detects a steered
angle of the outboard motor 3 (rotation angle of the steering shaft
8). The steered angle detection device 45 is configured to detect a
steered angle of the outboard motor 3 based on a movement amount of
the steering arm 43. The steered angle detection device 45 may
detect a steered angle of the outboard motor 3 based on not only a
movement amount of the steering arm 43 but also a movement amount
of a movable portion (for example, the ball screw 40 or the ball
nut 41) that is driven by the steering motor 17. In the example of
FIG. 3, the steered angle detection device 45 includes a steered
angle sensor 46 that detects a movement amount of the steering arm
43 as a movable portion, and a link mechanism 47 as a motion
transmitting device that transmits motion of the steering arm 43 to
the steered angle sensor 46.
[0074] As shown in FIG. 4, the electric steering apparatus 4
includes a plug 49 that closes a rotation stopper adjusting hole 48
penetrating through the outer wall of the steering housing 19, an
O-ring 53 that hermetically seals the gap between the outer
peripheral surface of the plug 49 and the inner peripheral surface
of the rotation stopper adjusting hole 48, and a rotation stopper
mechanism 54 that restricts rotation of the casing 36.
[0075] As shown in FIG. 4, the rotation stopper adjusting hole 48
penetrates through the outer wall of the steering housing 19 in the
thickness direction. Specifically, the rotation stopper adjusting
hole 48 penetrates through any of the housing main body 20, the
side covers 21, and the upper cover 22. FIG. 4 shows an example in
which the rotation stopper adjusting hole 48 is provided in the
front wall 23 of the steering housing 19. The rotation stopper
adjusting hole 48 extends from the outer surface of the steering
housing 19 toward the lock clutch 28. The rotation stopper
adjusting hole 48 is disposed at a position viewable from a
position on the hull H1. The rotation stopper adjusting hole 48 is
disposed farther forward than the casing 36 of the lock clutch 28.
The rotation stopper adjusting hole 48 and the casing 36 are
aligned in the front-rear direction in a plan view. The rotation
stopper adjusting hole 48 and the casing 36 face each other in the
radial directions Dr of the casing 36. When the rotation stopper
adjusting hole 48 is viewed from the forward side thereof, at least
a portion of the rotation stopper adjusting hole 48 overlaps the
casing 36.
[0076] As shown in FIG. 4, the rotation stopper adjusting hole 48
extends from the outer surface of the steering housing 19 to the
inner surface of the steering housing 19. FIG. 4 shows an example
in which the rotation stopper adjusting hole 48 is defined by a
stepped inner peripheral surface. The inner peripheral surface of
the rotation stopper adjusting hole 48 includes a cylindrical
large-diameter portion 48a that extends from the outer surface of
the steering housing 19 toward the inside of the steering housing
19, an annular portion 48b having a toric shape extending from the
large-diameter portion 48a to the inner side, and a cylindrical
small-diameter portion 48c extending from the annular portion 48b
to the inner surface of the steering housing 19. The diameter of
the large-diameter portion 48a is larger than the diameter of the
small-diameter portion 48c. A female screw portion 56 to which a
male screw portion 55 of the plug 49 is screwed is provided on the
large-diameter portion 48a.
[0077] As shown in FIG. 4, the plug 49 includes a disk-shaped plug
portion 51 provided with the male screw portion 55 on the outer
periphery, a columnar seal holding portion 52 that holds the O-ring
53, and an operation portion 50 to be operated by a user to attach
or detach the plug 49. The outer diameter of the plug portion 51 is
larger than the outer diameter of the seal holding portion 52. The
seal holding portion 52 is inserted into the O-ring 53. The O-ring
53 is disposed at a corner portion defined by an end face in the
axial direction of the plug portion 51 and the outer peripheral
surface of the seal holding portion 52. The seal holding portion 52
and the operation portion 50 extend to the sides opposite to each
other from the plug portion 51.
[0078] As shown in FIG. 5 and FIG. 6, the plug 49 is movable
between a closed position (position shown in FIG. 5) at which the
plug 49 closes the rotation stopper adjusting hole 48, and an open
position (position shown in FIG. 6) at which the plug 49 opens the
rotation stopper adjusting hole 48. The plug 49 is held at the
closed position by the male screw portion 55 and the female screw
portion 56. When the plug 49 is at the closed position, the plug
portion 51 is inserted into the large-diameter portion 48a of the
rotation stopper adjusting hole 48, and the seal holding portion 52
is inserted into the small-diameter portion 48c of the rotation
stopper adjusting hole 48. At this time, the O-ring 53 is
sandwiched in the axial direction by the end face in the axial
direction of the plug portion 51 and the annular portion 48b of the
rotation stopper adjusting hole 48. Accordingly, the gap between
the plug 49 and the rotation stopper adjusting hole 48 is
hermetically sealed. The operation portion 50 is disposed outside
the steering housing 19 when the plug 49 is at the closed position.
When a user picks the operation portion 50 and rotates the plug 49,
the plug 49 gradually moves toward the open position, and comes off
the steering housing 19. Accordingly, the rotation stopper
adjusting hole 48 is opened.
[0079] As shown in FIG. 5 and FIG. 6, the rotation stopper
mechanism 54 is a friction mechanism that restricts rotation of the
casing 36 by a frictional force acting between the pressed surface
57 to be pressed against the casing 36 and the casing 36. The
rotation stopper mechanism 54 is switched between a lock state in
which the rotation stopper mechanism 54 restricts rotation of the
casing 36 and a release state in which the rotation stopper
mechanism 54 releases the rotation restriction of the casing 36 by
weakening the pressing force on the pressed surface 57 against the
casing 36 to be smaller than in the lock state. The rotation
stopper mechanism 54 includes a tightening band 59 including an
inner surface on which the annular pressed surface 57 surrounding
the casing 36 is provided, and a pressing mechanism 58 that adjusts
the pressing force on the pressed surface 57 against the casing 36
by changing the inner diameter of the tightening band 59.
[0080] The tightening band 59 is preferably made of an elastic
material such as resin or rubber. As shown in FIG. 5 and FIG. 6,
the tightening band 59 includes a C-shaped band portion 60
surrounding the periphery of the casing 36 and a pair of bolt
insertion portions 61 extending outward in the radial directions
from both ends of the band portion 60 in the circumferential
direction. The band portion 60 is disposed inside the clutch
housing 33. The band portion 60 is disposed along the outer
peripheral surface of the casing 36. The pair of bolt insertion
portions 61 extend outward in the radial directions from the band
portion 60 toward the inner peripheral surface of the clutch
housing 33. The pair of bolt insertion portions 61 project outward
from a through-hole 63 penetrating through the clutch housing 33.
The pair of bolt insertion portions 61 include a pair of bolt
insertion holes 62 facing each other. The bolt insertion holes 62
are disposed outside the clutch housing 33. As shown in FIG. 4, the
pair of bolt insertion portions 61 are disposed between two
bearings 32 in the axial direction Da of the casing 36.
[0081] As shown in FIG. 5, the pressing mechanism 58 is disposed
around the lock clutch 28 inside the steering housing 19. The
pressing mechanism 58 includes a fastening bolt 64 inserted into
the pair of bolt insertion portions 61, and a bolt support portion
67 that supports a shaft portion 66 of the fastening bolt 64 so
that the pair of bolt insertion portions 61 are positioned between
the bolt support portion and the head portion 65 of the fastening
bolt 64. The pressing mechanism 58 further includes a ring-shaped
washer 68 interposed between the head portion 65 of the fastening
bolt 64 and the pair of bolt insertion portions 61, and a C-shaped
stopper ring 69 extending outward in the radial directions from the
shaft portion 66 of the fastening bolt 64.
[0082] As shown in FIG. 5, the shaft portion 66 of the fastening
bolt 64 is inserted into the bolt insertion holes 62 of the bolt
insertion portions 61. Further, the shaft portion 66 of the
fastening bolt 64 is inserted into an attaching hole 70 penetrating
through the bolt support portion 67 in the axial direction of the
fastening bolt 64. The bolt insertion holes 62 and the attaching
hole 70 are aligned in the axial direction of the fastening bolt
64. The outer diameter of the stopper ring 69 is larger than the
inner diameter of the attaching hole 70. The shaft portion 66 of
the fastening bolt 64 penetrates through the bolt support portion
67 in the axial direction of the fastening bolt 64. The stopper
ring 69 is disposed on the side opposite to the head portion 65 of
the fastening bolt 64 with respect to the bolt support portion 67.
The fastening bolt 64 is screwed to the bolt support portion 67 by
the male screw portion 71 provided on the outer periphery of the
shaft portion 66 of the fastening bolt 64 and the female screw
portion provided on the inner peripheral surface of the attaching
hole 70. The distance X1 between the head portion 65 of the
fastening bolt 64 and the end face of the bolt support portion 67
is adjusted by relative rotation of the male screw portion 71 and
the female screw portion.
[0083] As shown in FIG. 5, the pair of bolt insertion portions 61
of the tightening band 59 face each other in the axial direction of
the fastening bolt 64. The pair of bolt insertion portions 61 are
disposed between the head portion 65 of the fastening bolt 64 and
the end face of the bolt support portion 67. The pair of bolt
insertion portions 61 are sandwiched by the head portion 65 of the
fastening bolt 64 and the end face of the bolt support portion 67
via the washer 68. Accordingly, the inner peripheral surface of the
band portion 60, equivalent to the pressed surface 57, is pressed
against the outer peripheral surface of the casing 36. Therefore,
even when a force to rotate the casing 36 in the circumferential
direction is applied to the casing 36, a frictional force that
obstructs rotation of the casing 36 is generated between the
tightening band 59 and the casing 36, and rotation of the casing 36
is restricted.
[0084] As shown in FIG. 5, the pair of bolt insertion portions 61
of the tightening band 59 are fixed to the clutch housing 33 by
being sandwiched by the head portion 65 of the fastening bolt 64
and the end face of the bolt support portion 67. Accordingly,
rotation of the tightening band 59 with respect to the clutch
housing 33 is restricted. Therefore, in the state shown in FIG. 5
(lock state), rotation of the casing 36 with respect to the
tightening band 59 is restricted, and rotation of the tightening
band 59 with respect to the clutch housing 33 is restricted. The
clutch housing 33 is fixed to the steering housing 19 via the
steering motor 17. Therefore, in this state, rotation of the casing
36 with respect to the steering housing 19 is restricted.
[0085] When a user pushes the outboard motor 3 in the left-right
direction or resistance of water caused by cruising is applied to
the outboard motor 3, the force applied to the outboard motor 3 is
transmitted to the output shaft 35 of the lock clutch 28 via the
steering shaft 8. Specifically, a reverse input is generated. The
torque applied to the output shaft 35 is transmitted to the casing
36, and transmission of the torque from the output shaft 35 to the
input shaft 34 is shut off. As described above, in the state shown
in FIG. 5, rotation of the casing 36 with respect to the steering
housing 19 is restricted. Therefore, even when a reverse input is
generated in this state, the steered angle of the outboard motor 3
does not change. Accordingly, in this state, even if the steering
motor 17 is not driven, the steered angle of the outboard motor 3
is kept constant.
[0086] As shown in FIG. 6, the fastening bolt 64 includes a tool
attaching portion 73 provided on the head portion 65 of the
fastening bolt 64. The tool attaching portion 73 may be a recess
portion into which the tip end portion of a tool 74 such as a
screwdriver or a hexagonal wrench, or may be an outer peripheral
portion having a polygonal sectional shape to the periphery of
which a socket wrench is attached. FIG. 6 shows an example in which
a recess portion into which the tip end portion of the tool 74 is
inserted is provided on the end face of the head portion 65. The
distance X1 between the head portion 65 of the fastening bolt 64
and the end face of the bolt support portion 67 is adjusted by
rotating the fastening bolt 64 around the central axis thereof by a
user with use of the tool 74. The rotation stopper adjusting hole
48 is disposed on the center line of the fastening bolt 64. The
rotation stopper adjusting hole 48 is disposed ahead of the tool
attaching portion 73. The rotation stopper adjusting hole 48 faces
the tool attaching portion 73.
[0087] As shown in FIG. 6, to release the rotation restriction of
the casing 36 by the rotation stopper mechanism 54, the plug 49 is
removed from the rotation stopper adjusting hole 48 by a user. In
this state, the tool 74 is inserted into the rotation stopper
adjusting hole 48 by the user, and the tip end portion of the tool
74 is attached to the tool attaching portion 73 inside the steering
housing 19. Thereafter, the fastening bolt 64 is rotated around its
center line. Accordingly, the distance between the head portion 65
of the fastening bolt 64 and the end face of the bolt support
portion 67 gradually increases, and the inner diameter of the band
portion 60 gradually increases. Accordingly, the pressing force of
the band portion 60 against the outer peripheral surface of the
casing 36 decreases. Therefore, the restricting force applied to
the casing 36 by the tightening band 59 weakens, and the casing 36
becomes rotatable (release state) with respect to the tightening
band 59. Accordingly, the lock clutch 28 is disabled.
[0088] As shown in FIG. 6, in the release state, the pair of bolt
insertion portions 61 of the tightening band 59 are separated in
the axial direction of the fastening bolt 64. The inner diameter of
the band portion 60 in the release state is set to a diameter that
makes the casing 36 rotatable with respect to the band portion 60.
Further, in the release state, the stopper ring 69 attached to the
fastening bolt 64 is in contact with the bolt support portion 67.
In other words, the position of the stopper ring 69 is set so that
the stopper ring 69 is in contact with the bolt support portion 67
in the release state. When the stopper ring 69 comes into contact
with the bolt support portion 67, movement in the axial direction
of the fastening bolt 64 is restricted, so that the resistance in
the circumferential direction applied to the tool 74 via the
fastening bolt 64 increases. Therefore, based on the change in
resistance to be transmitted via the tool 74, it is confirmed that
the fastening bolt 64 has reached the release position (position
shown in FIG. 6) by a user.
[0089] To restore the rotation restriction of the casing 36 by the
rotation stopper mechanism 54, as in the case of releasing the
rotation stop, the fastening bolt 64 is rotated around its center
line by a user. Accordingly, the distance between the head portion
65 of the fastening bolt 64 and the end face of the bolt support
portion 67 gradually decreases, and the pair of bolt insertion
portions 61 gradually approach each other. Therefore, the inner
diameter of the band portion 60 of the tightening band 59 gradually
decreases, and the pressing force of the band portion 60 against
the outer peripheral surface of the casing 36 increases. Therefore,
the restricting force applied to the casing 36 by the tightening
band 59 increases, and rotation of the casing 36 with respect to
the steering housing 19 is restricted. Thereafter, the plug 49 is
attached to the rotation stopper adjusting hole 48 by the user.
[0090] As described above, in the first preferred embodiment, when
the rotation stopper mechanism 54 is in the lock state, rotation of
the casing 36 is restricted by the rotation stopper mechanism 54.
When a reverse input is generated, the force applied to the output
shaft 35 of the lock clutch 28 is transmitted to the casing 36. In
the lock state, rotation of the casing 36 is prevented, so that
even when a reverse input is generated in the lock state, rotations
of the output shaft 35 and the casing 36 are prevented. Therefore,
even when a user pushes the outboard motor 3 in the left-right
direction or a resistance of water caused by cruising is applied to
the outboard motor 3, the steered angle of the outboard motor 3
does not change. Therefore, even if the steering motor 17 is not
driven, the steered angle of the outboard motor 3 is kept
constant.
[0091] On the other hand, when the rotation stopper mechanism 54 is
in the release state, the rotation restriction of the casing 36 by
the rotation stopper mechanism 54 is released. In this state, when
a user pushes the outboard motor 3 in the left-right direction, the
force applied to the outboard motor 3 is transmitted to the output
shaft 35 via the steering shaft 8. Specifically, a reverse input is
generated. The force applied to the output shaft 35 is transmitted
to the casing 36. In the release state, the rotation restriction of
the casing 36 is released, so that the casing 36 rotates together
with the output shaft 35. In other words, in the release state, the
lock clutch 28 is disabled, so that when a user pushes the outboard
motor 3, the outboard motor 3 accordingly turns in the left-right
direction.
[0092] Thus, the rotation stopper mechanism 54 enables the lock
clutch 28 by restricting the rotation of the casing 36, and on the
other hand, the rotation stopper mechanism 54 disables the lock
clutch 28 by releasing the rotation restriction of the casing 36.
Therefore, a user can manually steer the outboard motor 3 without
shutting off the driving force transmission path (without shutting
off the physical connection from the steering motor 17 to the
steering shaft 8). Therefore, the adjusting operation after manual
steering is eliminated. Further, the user can turn the outboard
motor 3 in the left-right direction by directly pushing the
outboard motor 3, so that the user can easily move the outboard
motor 3 to a target steered angle in a short time. In addition, the
rotation stopper mechanism 54 is only required to make the lock
clutch 28 itself rotatable, so that a simple structure is applied
to the rotation stopper mechanism 54. Accordingly, a complicated
rotation stopper mechanism 54 is not required.
[0093] In the first preferred embodiment, the casing 36 is
supported rotatably by the bearings 32. Therefore, when a torque is
applied to the casing 36 while the rotation stopper mechanism 54 is
in the release state, the casing 36 smoothly rotates. If the casing
36 does not smoothly rotate, when manually steering the outboard
motor 3, resistance to be applied to the outboard motor 3 may
increase, and the outboard motor 3 may not smoothly move in the
left-right direction. Therefore, by supporting the casing 36
rotatably by the bearings 32, the outboard motor 3 is manually
smoothly steered with a smaller force.
[0094] In the first preferred embodiment, the steering motor 17 and
the lock clutch 28 are protected from water (including seawater and
fresh water) by the steering housing 19. Further, the rotation
stopper adjusting hole 48 extending from the outside of the
steering housing 19 toward the lock clutch 28 is provided in the
steering housing 19, so that a user can operate the rotation
stopper mechanism 54 from the outside of the steering housing 19
through the rotation stopper adjusting hole 48. Specifically, a
user can operate the rotation stopper mechanism 54 without
inserting his/her hand into the steering housing 19. In addition,
the plug 49 configured to open and close the rotation stopper
adjusting hole 48 is provided, so that the sealing property of the
steering housing 19 when the operation of the rotation stopper
mechanism 54 is unnecessary is improved. Accordingly, the
components disposed inside the steering housing 19 (steering motor
17, etc.) are more reliably protected from water.
[0095] In the first preferred embodiment, the rotation stopper
adjusting hole 48 provided in the steering housing 19 is disposed
at a position viewable from a position on the hull H1. Therefore, a
user can operate the rotation stopper mechanism 54 from a position
on the hull H1.
[0096] In the first preferred embodiment, the rotation stopper
adjusting hole 48 provided in the steering housing 19 faces the
casing 36 in the radial directions Dr of the casing 36. In other
words, at least a portion of the rotation stopper adjusting hole 48
is disposed at the same position as the casing 36 in the axial
direction Da of the casing 36. Therefore, the distance between the
rotation stopper adjusting hole 48 and the casing 36 becomes
shorter than in the case where the rotation stopper adjusting hole
48 and the casing 36 deviate from each other in the axial
direction. If the distance between the rotation stopper adjusting
hole 48 and the casing 36 is long, other members may be interposed
between the rotation stopper adjusting hole 48 and the casing 36
and complicates the path from the rotation stopper adjusting hole
48 to the rotation stopper mechanism 54. Therefore, a path from the
rotation stopper adjusting hole 48 to the rotation stopper
mechanism 54 is prevented from being complicated by reducing the
distance between the rotation stopper adjusting hole 48 and the
casing 36.
[0097] In the first preferred embodiment, the pressed surface 57
provided on the rotation stopper mechanism 54 (friction mechanism)
is pressed against the outer peripheral surface of the casing 36.
In the lock state, rotation of the casing 36 is restricted by a
frictional force acting between the pressed surface 57 and the
casing 36. In the release state, the pressing force on the pressed
surface 57 against the casing 36 is weakened to be smaller than in
the lock state, and accordingly, the frictional force acting
between the pressed surface 57 and the casing 36 is weakened to be
smaller than in the lock state. Accordingly, the rotation
restriction of the casing 36 is released.
[0098] Thus, the state of the rotation stopper mechanism 54 is
switched by changing the pressing force on the pressed surface 57
against the casing 36. Therefore, the rotation stopper mechanism 54
enables and disables the lock clutch 28 without shutting off the
driving force transmission path. Further, the position at which the
pressed surface 57 is pressed may be an arbitrary position of the
casing 36 as long as the position causes restriction of the
rotation of the casing 36, so that it is not necessary to return
the casing 36 to the original position (position before the
outboard motor 3 is manually steered) when the lock clutch 28 is
enabled again after the outboard motor 3 is manually steered.
Therefore, the adjusting operation to enable the lock clutch 28
again is eliminated.
[0099] In the first preferred embodiment, the pressed surface 57 to
be pressed against the outer peripheral surface of the casing 36 is
provided on the inner surface of the tightening band 59 of the
rotation stopper mechanism 54 (friction mechanism). The inner
diameter of the tightening band 59 is changed by the pressing
mechanism 58. Accordingly, the pressing force on the pressed
surface 57 against the casing 36 is increased or decreased, and the
state of the rotation stopper mechanism 54 is switched. The
pressing surface 57 preferably has an annular shape surrounding the
casing 36. Therefore, the contact area between the pressed surface
57 and the casing 36 increases. In addition, the tightening band 59
surrounds the entire circumference of the casing 36 in the lock
state, so that the contact area between the pressed surface 57 and
the casing 36 further increases. Therefore, the casing 36 is
reliably held by the tightening band 59. Accordingly, the rotation
stopper mechanism 54 more reliably restricts rotation of the casing
36 in the lock state.
Second Preferred Embodiment
[0100] Next, a second preferred embodiment of the present invention
is described. In FIG. 7 and FIG. 8 described below, components
equivalent to those shown in FIG. 1 to FIG. 6 described above are
designated by the same reference symbols as in FIG. 1, etc., and
description thereof is omitted.
[0101] As shown in FIG. 8, an electric steering apparatus 4
according to the second preferred embodiment includes, instead of
the rotation stopper mechanism 54 according to the first preferred
embodiment, a rotation stopper mechanism 254 that presses a contact
member 259 provided with a pressed surface 257 against the casing
36 in the radial direction Dr of the casing 36. The rotation
stopper mechanism 254 is a friction mechanism including the contact
member 259 provided with the pressed surface 257 and a pressing
mechanism 258 that changes the force to push the contact member 259
toward the casing 36.
[0102] As shown in FIG. 7, the contact member 259 is disposed
between the two bearings 32 in the axial direction Da of the casing
36. The contact member 259 is disposed inside the clutch housing
33. As shown in FIG. 8, the contact member 259 preferably has a
tabular shape. The contact member 259 is disposed along the outer
peripheral surface of the casing 36. The contact member 259 is
accommodated in an accommodating recess portion 275 provided on the
clutch housing 33. The accommodating recess portion 275 extends
outward in the radial directions from the inner peripheral surface
of the clutch housing 33. The contact member 259 is movable in the
radial directions Dr of the casing 36 with respect to the
accommodating recess portion 275. The movement of the contact
member 259 in the circumferential direction Dc of the casing 36 is
restricted by the contact between the contact member 259 and the
inner surface of the accommodating recess portion 275.
[0103] As shown in FIG. 8, the end face of the contact member 259
faces the outer peripheral surface of the casing 36. The pressed
surface 257 is provided on the end face of the contact member 259.
The pressed surface 257 faces the outer peripheral surface of the
casing 36 at a fixed interval. In the example shown in FIG. 8, the
outer peripheral surface of the casing 36 is cylindrical or
substantially cylindrical, so that the pressed surface 257
preferably has an arc sectional shape along the outer peripheral
surface of the casing 36. The sectional shape of the pressed
surface 257 may not be an arc as long as the pressed surface 257
has a shape facing the outer peripheral surface of the casing 36 at
a fixed interval. For example, when the outer peripheral surface of
the casing 36 is polygonal (for example, octagonal), the sectional
shape of the pressed surface 257 may be linear.
[0104] As shown in FIG. 8, the pressing mechanism 258 is disposed
around the lock clutch 28 inside the steering housing 19. The
pressing mechanism 258 is disposed between the rotation stopper
adjusting hole 48 and the contact member 259. The pressing
mechanism 258 includes a fastening bolt movable between a lock
position (position shown in FIG. 7 and FIG. 8) at which the pressed
surface 257 is pressed against the casing 36, and a release
position at which the pressing force on the pressed surface 257
against the casing 36 becomes smaller than in the case where the
fastening bolt 64 is at the lock position, and a spring 276
interposed between the fastening bolt 64 and the contact member
259. The spring 276 is preferably a coil spring or a leaf
spring.
[0105] As shown in FIG. 8, the fastening bolt 64 is inserted into a
female screw hole 277 penetrating through the clutch housing 33 in
its thickness direction. The fastening bolt 64 is held in a posture
orthogonal or substantially orthogonal to the center line CL of the
casing 36 by the clutch housing 33. The head portion 65 of the
fastening bolt 64 is disposed outside the clutch housing 33, and
the shaft portion 66 of the fastening bolt 64 is disposed between
the head portion 65 of the fastening bolt 64 and the contact member
259. The spring 276 is sandwiched by the shaft portion 66 of the
fastening bolt 64 and the contact member 259. The rotation stopper
adjusting hole 48 is disposed on the center line of the fastening
bolt 64. The head portion 65 of the fastening bolt 64 is disposed
on the rear side of the rotation stopper adjusting hole 48. The
head portion 65 of the fastening bolt 64 faces the rotation stopper
adjusting hole 48.
[0106] FIG. 8 shows a state in which the fastening bolt 64 is at
the lock position. In this state, the contact member 259 is pressed
against the casing 36 in the radial directions Dr of the casing 36.
Therefore, even if a force to rotate the casing 36 in the
circumferential direction thereof is applied to the casing 36, a
frictional force that obstructs rotation of the casing 36 is
generated between the contact member 259 and the casing 36, and the
rotation of the casing 36 is restricted. Further, the contact
member 259 is restricted from moving in the circumferential
direction Dc of the casing 36 by the inner surface of the
accommodating recess portion 275. Therefore, even if a reverse
input is generated in this state, the steered angle of the outboard
motor 3 does not change.
[0107] To release the rotation restriction of the casing 36 by the
rotation stopper mechanism 254, the plug 49 is removed from the
rotation stopper adjusting hole 48 by a user. In this state, a tool
is inserted into the rotation stopper adjusting hole 48 by the
user, and the tip end portion of the tool is attached to the tool
attaching portion 73 inside the steering housing 19. Thereafter,
the fastening bolt 64 is rotated around its center line.
Accordingly, the fastening bolt 64 gradually moves outward in the
radial directions, and the distance in the radial directions
between the fastening bolt 64 and the casing 36 increases.
Therefore, the force of the spring 276 to push the contact member
259 inward in the radial directions weakens. Therefore, the
restricting force applied by the contact member 259 to the casing
36 weakens, and the casing 36 becomes rotatable (release state)
with respect to the contact member 259. Accordingly, the lock
clutch 28 is disabled.
[0108] To restore the rotation restriction of the casing 36 by the
rotation stopper mechanism 254, as in the case of releasing the
rotation stop, the fastening bolt 64 is rotated around its center
line by a user. Accordingly, the fastening bolt 64 gradually
approaches the casing 36, and the distance in the radial directions
between the fastening bolt 64 and the casing 36 decreases.
Therefore, the force of the spring 276 to push the contact member
259 inward in the radial directions increases. Therefore, the
restricting force applied by the contact member 259 to the casing
36 increases, and the rotation of the casing 36 with respect to the
steering housing 19 is restricted. Thereafter, the plug 49 is
attached to the rotation stopper adjusting hole 48 by the user.
[0109] As described above, in the second preferred embodiment, the
pressed surface 257 to be pressed against the outer peripheral
surface of the casing 36 is provided on the contact member 259 of
the rotation stopper mechanism 254 (friction mechanism). The force
to push the contact member 259 toward the casing 36 is changed by
the pressing mechanism 258. Accordingly, the pressing force on the
pressed surface 257 against the casing 36 is increased or
decreased, and the state of the rotation stopper mechanism 254 is
switched. Therefore, the rotation stopper mechanism 254 enables and
disables the lock clutch 28 without shutting off the driving force
transmission path.
Third Preferred Embodiment
[0110] Next, a third preferred embodiment of the present invention
is described. In FIG. 9 and FIG. 10 described below, the components
equivalent to those shown in FIG. 1 to FIG. 8 are designated by the
same reference symbols as in FIG. 1, etc., and description thereof
is omitted.
[0111] As shown in FIG. 10, an electric steering apparatus 4
according to the third preferred embodiment includes, instead of
the rotation stopper mechanism 54 according to the first preferred
embodiment, a rotation stopper mechanism 354 that restricts
rotation of the casing 36 by a stopper bolt 364 that is orthogonal
or substantially orthogonal to the center line CL of the casing 36
and extends along a straight line passing through the center line
CL. The rotation stopper mechanism 354 is a stopper mechanism
including a plurality of rotation stopper portions 378 recessed
inward in the radial directions on the outer peripheral portion of
the casing 36, and a stopper bolt 364 movable between a lock
position (position shown in FIG. 10) at which the stopper bolt 364
faces any of the plurality of rotation stopper portions 378 and a
release position (position shown in FIG. 9) at which facing to the
plurality of rotation stopper portions 378 is released.
[0112] As shown in FIG. 9, the plurality of rotation stopper
portions 378 are disposed between the two bearings 32 in the axial
direction Da of the casing 36. As shown in FIG. 10, the plurality
of rotation stopper portions 378 are provided on the outer
peripheral portion of the casing 36. The plurality of rotation
stopper portions 378 are aligned at intervals in the
circumferential direction Dc of the casing 36. The rotation stopper
portions 378 are recessed inward in the radial directions from the
outer peripheral surface of the casing 36. The rotation stopper
portions 378 are opened at the outer peripheral surface of the
casing 36. Each rotation stopper portion 378 includes a pair of
facing portions 379 facing each other in the circumferential
direction Dc of the casing 36. The pair of facing portions 379 face
each other at an interval in the circumferential direction Dc of
the casing 36.
[0113] As shown in FIG. 10, the stopper bolt 364 is inserted into a
female screw hole 277 of the clutch housing 33. The stopper bolt
364 is held in a posture orthogonal or substantially orthogonal to
the center line CL of the casing 36 by the clutch housing 33. The
head portion 65 of the stopper bolt 364 is disposed outside the
clutch housing 33, and the shaft portion 66 of the stopper bolt 364
is disposed between the head portion 65 of the stopper bolt 364 and
the casing 36. The rotation stopper adjusting hole 48 is disposed
on the center line of the stopper bolt 364. The head portion 65 of
the stopper bolt 364 is disposed on the rear side of the rotation
stopper adjusting hole 48. The head portion 65 of the stopper bolt
364 faces the rotation stopper adjusting hole 48. The tool
attaching portion 73 is provided on the head portion 65 of the
stopper bolt 364.
[0114] The stopper bolt 364 is movable between the lock position
(position shown in FIG. 10) and the release position (position
shown in FIG. 9) with respect to the casing 36 and the clutch
housing 33. The lock position is a position at which a portion of
the stopper bolt 364 is accommodated in any of the plurality of
rotation stopper portions 378. The release position is a position
at which the whole stopper bolt 364 is disposed farther outward in
the radial directions than the plurality of rotation stopper
portions 378. In the state shown in FIG. 10, the shaft portion 66
of the stopper bolt 364 is accommodated in one rotation stopper
portion 378. Therefore, the shaft portion 66 of the stopper bolt
364 is disposed between the pair of facing portions 379, and face
both facing portions 379 in the circumferential direction Dc of the
casing 36. As viewed in the axial direction Da of the casing 36,
the pair of facing portions 379 are disposed on the sides opposite
to each other with respect to the stopper bolt 364.
[0115] When a user pushes the outboard motor 3 in the left-right
direction or a resistance of water caused by cruising is applied to
the outboard motor 3, a reverse input is generated, and as a
result, a force to rotate the casing 36 clockwise or
counterclockwise is applied to the casing 36. In the state shown in
FIG. 10 (lock state), the shaft portion 66 of the stopper bolt 364
is disposed between the pair of facing portions 379 in the
circumferential direction. Therefore, in this state, when a
clockwise torque is applied to the casing 36, due to contact
between one of the pair of facing portions 379 and the stopper bolt
364, clockwise rotation of the casing 36 is restricted. Similarly,
in this state, when a counterclockwise torque is applied to the
casing 36, due to contact between the other one of the pair of
facing portions 379 and the stopper bolt 364, counterclockwise
rotation of the casing 36 is restricted. Therefore, even if a
reverse input is generated in this state, the steered angle of the
outboard motor 3 does not change.
[0116] To release the rotation restriction of the casing 36 by the
rotation stopper mechanism 354, the plug 49 is removed from the
rotation stopper adjusting hole 48 by a user. In this state, a tool
is inserted into the rotation stopper adjusting hole 48 by the
user, and the tip end portion of the tool is attached to the tool
attaching portion 73 inside the steering housing 19. Thereafter,
the stopper bolt 364 is rotated around its center line.
Accordingly, the stopper bolt 364 gradually moves outward in the
radial directions, and the distance in the radial directions
between the stopper bolt 364 and the casing 36 increases.
Therefore, the stopper bolt 364 comes off the rotation stopper
portion 378, and facing between the stopper bolt 364 and the
rotation stopper portion 378 is released. Therefore, the casing 36
becomes rotatable (release state) with respect to the steering
housing 19. Accordingly, the lock clutch 28 is disabled.
[0117] To restore the rotation restriction of the casing 36 by the
rotation stopper mechanism 354, the casing 36 is disposed at a
position at which any of the plurality of rotation stopper portions
378 faces the stopper bolt 364 in the radial directions Dr of the
casing 36. For example, by turning the outboard motor 3 in the
left-right direction by a user, the position of the casing 36 in
the circumferential direction is adjusted. Thereafter, as in the
case of releasing the rotation stop, the stopper bolt 364 is
rotated around its center line by the user. Accordingly, the
stopper bolt 364 gradually approaches the casing 36, and the shaft
portion 66 of the stopper bolt 364 is inserted into the rotation
stopper portion 378. Accordingly, rotation of the casing 36 with
respect to the steering housing 19 is restricted. Thereafter, the
plug 49 is attached to the rotation stopper adjusting hole 48 by
the user.
[0118] As described above, in the third preferred embodiment, in
the lock state, the stopper bolt 364 is disposed at the lock
position (position at which the stopper bolt 364 comes into contact
or is contactable with the casing 36). Even if a torque is applied
to the casing 36 in the lock state, rotation of the casing 36 is
restricted by contact between the casing 36 and the stopper bolt
364. In the release state, the stopper bolt 364 is disposed at the
release position (position at which the stopper bolt 364 cannot
come into contact with the casing 36). Accordingly, the rotation
restriction of the casing 36 is released. Thus, the state of the
rotation stopper mechanism 354 is switched by changing the position
of the stopper bolt 364. Therefore, the rotation stopper mechanism
354 enables and disables the lock clutch 28 without shutting off
the driving force transmission path.
[0119] Further, the rotation stopper mechanism 354 includes a
plurality of rotation stopper portions 378 aligned in the
circumferential direction Dc of the casing 36. The stopper bolt 364
restricts rotation of the casing 36 regardless of which of the
rotation stopper portions 378 the stopper bolt 364 faces.
Therefore, to enable the lock clutch 28 again after the outboard
motor 3 is manually steered, it is not necessary to return the
casing 36 to the original position (position before the outboard
motor 3 is manually steered). Therefore, the adjusting operation to
enable the lock clutch 28 again is eliminated.
Fourth Preferred Embodiment
[0120] Next, a fourth preferred embodiment of the present invention
is described. In FIG. 11 to FIG. 13 described below, components
equivalent to those shown in FIG. 1 to FIG. 10 described above are
designated by the same reference symbols as in FIG. 1, etc., and
description thereof is omitted.
[0121] As shown in FIG. 12, an electric steering apparatus 4
according to a fourth preferred embodiment includes, instead of the
rotation stopper mechanism 54 according to the first preferred
embodiment, the rotation stopper mechanism 454 that restricts
rotation of the casing 36 by a stopper bolt 364 orthogonal or
substantially orthogonal to the center line CL of the casing 36 and
extending along a straight line that does not cross the center line
CL. The rotation stopper mechanism 454 is a stopper mechanism
including a plurality of rotation stopper portions 478 recessed
inward in the radial directions on the outer peripheral portion of
the casing 36, and a stopper bolt 364 movable between a lock
position (position shown in FIG. 12) at which the stopper bolt 364
faces any of the plurality of rotation stopper portions 478 and a
release position (position shown in FIG. 11) at which the stopper
bolt 364 faces to the plurality of rotation stopper portions 478 is
released.
[0122] As shown in FIG. 11, the plurality of rotation stopper
portions 478 are disposed between the two bearings 32 in the axial
direction Da of the casing 36. As shown in FIG. 12 and FIG. 13, the
plurality of rotation stopper portions 478 are provided on the
outer peripheral portion of the casing 36. The plurality of
rotation stopper portions 478 are aligned in the circumferential
direction Dc of the casing 36. The sectional shape of the plurality
of rotation stopper portions 478 orthogonal or substantially
orthogonal to the center line CL of the casing 36 is preferably
polygonal. Each rotation stopper portion 478 defines a groove
recessed inward in the radial direction from the outer peripheral
surface of the casing 36. Each rotation stopper portion 478 is
opened at the outer peripheral surface of the casing 36. Each
rotation stopper portion 478 extends along a straight line that is
orthogonal or substantially orthogonal to the center line CL of the
casing 36 and does not cross the center line CL. Each rotation
stopper portion 478 includes a pair of facing portions 479 aligned
in the direction orthogonal or substantially orthogonal to the
center line CL of the casing 36. Rotation of the casing 36 is
restricted by contact between the pair of facing portions 479 and
the stopper bolt 364.
[0123] As shown in FIG. 12, the stopper bolt 364 is inserted into a
female screw hole 277 of the clutch housing 33. The stopper bolt
364 is held in a posture orthogonal or substantially orthogonal to
the center line CL of the casing 36 by the clutch housing 33. The
head portion 65 of the stopper bolt 364 is disposed outside the
clutch housing 33, and the shaft portion 66 of the stopper bolt 364
is disposed over the casing 36. The rotation stopper adjusting hole
48 is disposed on the center line of the stopper bolt 364. The head
portion 65 of the stopper bolt 364 is disposed on the rear side of
the rotation stopper adjusting hole 48. The head portion 65 of the
stopper bolt 364 faces the rotation stopper adjusting hole 48.
[0124] As shown in FIG. 12, the stopper bolt 364 is movable between
the lock position (position shown in FIG. 12 and FIG. 13) and the
release position (position shown in FIG. 11) with respect to the
casing 36 and the clutch housing 33. The lock position is a
position at which a portion of the stopper bolt 364 is accommodated
in any of the plurality of rotation stopper portions 478. The
release position is a position at which the whole stopper bolt 364
is disposed farther outward in the radial directions than the
plurality of rotation stopper portions 478. In the state shown in
FIG. 12, the shaft portion 66 of the stopper bolt 364 is
accommodated in one rotation stopper portion 478. Therefore, the
shaft portion 66 of the stopper bolt 364 faces both facing portions
479 provided on the same rotation stopper portion 478. As viewed in
the axial direction Da of the casing 36, the pair of facing
portions 479 are disposed on the same side with respect to the
stopper bolt 364.
[0125] When a force to turn the outboard motor 3 in the left-right
direction is applied to the outboard motor 3 without passing
through the steering shaft 8, a reverse input is generated, and as
a result, a force to rotate the casing 36 clockwise or
counterclockwise is applied to the casing 36. In the state (lock
state) shown in FIG. 12, the shaft portion 66 of the stopper bolt
364 faces the pair of facing portions 479 in the up-down direction.
Therefore, in this state, when a clockwise torque is applied to the
casing 36, due to contact between one of the pair of facing
portions 479 and the stopper bolt 364, clockwise rotation of the
casing 36 is restricted. Similarly, when a counterclockwise torque
is applied to the casing 36 in this state, due to contact between
the other one of the pair of facing portions 479 and the stopper
bolt 364, counterclockwise rotation of the casing 36 is restricted.
Therefore, even when a reverse input is generated in this state,
the steered angle of the outboard motor 3 does not change.
[0126] To release the rotation restriction of the casing 36 by the
rotation stopper mechanism 454, the plug 49 is removed from the
rotation stopper adjusting hole 48 by a user. In this state, a tool
is inserted into the rotation stopper adjusting hole 48 by the
user, and the tip end portion of the tool is attached to the tool
attaching portion 73 inside the steering housing 19. Thereafter,
the stopper bolt 364 is rotated around its center line.
Accordingly, the stopper bolt 364 gradually moves outward in the
radial directions. Therefore, the stopper bolt 364 comes off the
rotation stopper portion 478, and facing between the stopper bolt
364 and the rotation stopper portion 478 is released. Therefore,
the casing 36 becomes rotatable (release state) with respect to the
steering housing 19. Accordingly, the lock clutch 28 is
disabled.
[0127] To restore the rotation restriction of the casing 36 by the
rotation stopper mechanism 454, the casing 36 is disposed at a
position at which any of the plurality of rotation stopper portions
478 extends along the center line of the stopper bolt 364 and the
female screw hole 277. For example, by turning the outboard motor 3
in the left-right direction by the user, the position of the casing
36 in the circumferential direction is adjusted. Thereafter, as in
the case of releasing the rotation stop, the stopper bolt 364 is
rotated around its center line by the user. Accordingly, the
stopper bolt 364 gradually approaches the casing 36, and the shaft
portion 66 of the stopper bolt 364 is inserted into the rotation
stopper portion 478. Accordingly, rotation of the casing 36 with
respect to the steering housing 19 is restricted. Thereafter, the
plug 49 is attached to the rotation stopper adjusting hole 48 by
the user.
[0128] As described above, in the fourth preferred embodiment, a
stopper bolt 364 as a stopper member is provided in the rotation
stopper mechanism 454 (stopper mechanism). In the lock state, the
stopper bolt 364 is disposed at the lock position (position at
which the stopper bolt 364 comes into contact or is contactable
with the casing 36). Therefore, even if a torque is applied to the
casing 36 in the lock state, rotation of the casing 36 is
restricted by contact between the casing 36 and the stopper bolt
364. In the release state, the stopper bolt 364 is disposed at the
release position (position at which the stopper bolt 364 cannot
come into contact with the casing 36). Accordingly, the rotation
restriction of the casing 36 is released. Thus, the state of the
rotation stopper mechanism 454 is switched by changing the position
of the stopper bolt 364. Further, the plurality of rotation stopper
portions 478 are aligned in the circumferential direction Dc of the
casing 36, so that the adjusting operation to enable the lock
clutch 28 again is eliminated.
Other Preferred Embodiments
[0129] Although first to fourth preferred embodiments of the
present invention have been described above, the present invention
is not restricted to the contents of the first to fourth preferred
embodiments and various modifications are possible within the scope
of the present invention.
[0130] For example, in the first to fourth preferred embodiments
described above, the case where the plug 49 preferably is movable
independently of the fastening bolt 64 and the stopper bolt 364 is
described. However, the plug 49 and the fastening bolt 64 may be
configured to rotate integrally. Specifically, as shown in FIG. 14,
an operation member 564 serving as both of the plug 49 and the
fastening bolt 64 may be provided in the electric steering
apparatus 4. Similarly, an operation member serving as both of the
plug 49 and the stopper bolt 364 may be provided in the electric
steering apparatus 4. The operation member 564 may be an integral
member shown in FIG. 14, or may be a plurality of members joined to
each other.
[0131] When the operation member 564 is provided, according to an
operation of the operation member 564 by a user, the rotation
stopper mechanism 54 is switched between the lock state and the
release state. As shown in FIG. 14, a portion of the operation
member 564 is disposed inside the rotation stopper adjusting hole
48 opened at the outer surface of the steering housing 19.
Therefore, the user can operate the operation member 564 without
removing the operation member 564 from the rotation stopper
adjusting hole 48. Further, the user is not required to insert a
portion of the tool into the steering housing 19 through the
rotation stopper adjusting hole 48, so that the user can more
easily operate the rotation stopper mechanism 54.
[0132] In the first to fourth preferred embodiments described
above, the case where the casing 36 is supported by the clutch
housing 33 via the bearings 32 is described. However, the casing 36
may be directly supported by the clutch housing 33. Specifically,
the bearings 32 may be omitted.
[0133] In the first to fourth preferred embodiments described
above, the case where the rotation stopper adjusting hole 48 closed
by the plug 49 is provided in the front wall 23 of the steering
housing 19, and is disposed at a position viewable from a position
on the hull H1, is described. However, the rotation stopper
adjusting hole 48 may be provided in a portion other than the front
wall 23 of the steering housing 19, and may not be viewable from a
position on the hull H1. The rotation stopper adjusting hole 48 and
the plug 49 may be omitted. In this case, the rotation stopper
mechanism 54 may be operated in a state in which at least one of
the side covers 21 and the upper cover 22 is removed.
[0134] In the first to fourth preferred embodiments described
above, the case where the rotation stopper adjusting hole 48 and
the casing 36 face each other in the radial directions Dr of the
casing 36 is described. However, the rotation stopper adjusting
hole 48 and the casing 36 may not face in the radial directions.
For example, the whole rotation stopper adjusting hole 48 may be
disposed at a position different from the position of the casing 36
in the axial direction Da of the casing 36.
[0135] In the first to fourth preferred embodiments described
above, the case where the O-ring 53 is held by the seal holding
portion 52 of the plug 49 is described. However, an annular groove
that accommodates the O-ring 53 may be provided on the outer
peripheral portion of the plug portion 51. In this case, the seal
holding portion 52 may be omitted. The O-ring 53 may be held not by
the plug 49 but by the steering housing 19 inside the rotation
stopper adjusting hole 48.
[0136] In the first to fourth preferred embodiments described
above, the case where the fastening bolt 64 and the stopper bolt
364 are directly operated by a user is described. However, an
electric actuator that rotates the fastening bolt 64 may be
provided. Similarly, an electric actuator that rotates the stopper
bolt 364 may be provided. Specifically, the fastening bolt 64 and
the stopper bolt 364 may be automatically operated according to a
user's command.
[0137] In the first preferred embodiment described above, the case
where the tightening band 59 is preferably made of an elastic
material such as resin or rubber is described. However, the
tightening band 59 may be made of a material other than resin and
rubber.
[0138] In the first preferred embodiment described above, the case
where the washer 68 and the stopper ring 69 preferably are attached
to the fastening bolt 64 is described. However, one or both of the
washer 68 and the stopper ring 69 may be omitted.
[0139] In the second preferred embodiment described above, the case
where the contact member 259 preferably is pushed by the fastening
bolt 64 via the spring 276 is described. However, the shaft portion
66 of the fastening bolt 64 may come into contact with the contact
member 259, and the contact member 259 may be directly pushed by
the fastening bolt 64. Specifically, the spring 276 interposed
between the fastening bolt 64 and the contact member 259 may be
omitted.
[0140] In the third and fourth preferred embodiments described
above, the case where the plurality of rotation stopper portions
378 preferably are provided on the casing 36 is described. However,
the number of rotation stopper portions 378 provided on the casing
36 may be one.
[0141] Also, features of two or more of the various preferred
embodiments described above may be combined.
[0142] The present invention corresponds to Japanese Patent
Application No. 2013-206512 filed on Oct. 1, 2013 in the Japan
Patent Office, and the entire disclosure of this application is
incorporated herein by reference.
[0143] While preferred embodiments of the present invention have
been described above, it is to be understood that variations and
modifications will be apparent to those skilled in the art without
departing from the scope and spirit of the present invention. The
scope of the present invention, therefore, is to be determined
solely by the following claims.
* * * * *